FIG. 1 shows an M2M communication system. The system includes a bearer network and M2M nodes communicating via the bearer network. The M2M nodes include an application node, an intermediate node and a base node. The M2M nodes communicate with each other via the bearer network, each M2M node including, at least, an Application Entity (AE) or a Common Service Entity (CSE).
The AE is a logic unit for executing an actual M2M application, and the CSE is a logic unit for managing and serving the application. The communication between M2M applications is information interaction via the CSEs. The M2M applications are registered onto the CSEs, the CSEs also need to be registered onto each other, and interaction between the M2M applications can be implemented via the communication between the CSEs.
The application node is an executive node at a tail end such as a smart electric meter, a temperature measurement and control sensor, a fire alarm and a smart home appliance, etc. The intermediate node is middleware connecting the executive node at the tail end to a network-side server, such as a gateway. The base node is the network-side server. An application registered onto the base node may be a management platform of an M2M service provider.
In FIG. 1, an AE on an application node is registered onto a CSE on an intermediate node, so the CSE on the intermediate node is called as a local CSE or a registering CSE of the AE on the application node. Similarly, the CSE on the intermediate node is registered onto a CSE on a base node, and the CSE on the base node is called as a local CSE or a registering CSE of the CSE on the intermediate node.
It is found, in the conventional art, that when an M2M node is re-registered onto a registering CSE thereof after being deleted due to failure or other reasons, data of an AE and a CSE on the M2M node stored on the registering CSE thereof is lost, thus resulting in data loss after the failure of the M2M node are removed.